java.io
class FileOutputStream

java.lang.Object java.io.OutputStream java.io.FileOutputStream

All Implemented Interfaces:

Closeable, Flushable

Most common ways to construct:

File file = …;

FileOutputStream fos = new FileOutputStream(file);

Based on 108 examples

 

String strFilePath = …;

FileOutputStream fos = new FileOutputStream(strFilePath);

Based on 77 examples

public class FileOutputStream
extends OutputStream

A file output stream is an output stream for writing data to a File or to a FileDescriptor. Whether or not a file is available or may be created depends upon the underlying platform. Some platforms, in particular, allow a file to be opened for writing by only one FileOutputStream (or other file-writing object) at a time. In such situations the constructors in this class will fail if the file involved is already open.

FileOutputStream is meant for writing streams of raw bytes such as image data. For writing streams of characters, consider using FileWriter.

See Also (auto-generated):

File

FileInputStream

OutputStream

FileOutputStream

public FileOutputStream(File file)
                 throws FileNotFoundException

Creates a file output stream to write to the file represented by the specified File object. A new FileDescriptor object is created to represent this file connection.

First, if there is a security manager, its checkWrite method is called with the path represented by the file argument as its argument.

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:

file - the file to be opened for writing.

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason

FileOutputStream

public FileOutputStream(File file,
                        boolean append)
                 throws FileNotFoundException

Creates a file output stream to write to the file represented by the specified File object. If the second argument is true, then bytes will be written to the end of the file rather than the beginning. A new FileDescriptor object is created to represent this file connection.

First, if there is a security manager, its checkWrite method is called with the path represented by the file argument as its argument.

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:

file - the file to be opened for writing.

append - if true, then bytes will be written to the end of the file rather than the beginning

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason

FileOutputStream

public FileOutputStream(FileDescriptor fdObj)

Creates an output file stream to write to the specified file descriptor, which represents an existing connection to an actual file in the file system.

First, if there is a security manager, its checkWrite method is called with the file descriptor fdObj argument as its argument.

Parameters:

fdObj - the file descriptor to be opened for writing

FileOutputStream

public FileOutputStream(String name)
                 throws FileNotFoundException

Creates an output file stream to write to the file with the specified name. A new FileDescriptor object is created to represent this file connection.

First, if there is a security manager, its checkWrite method is called with name as its argument.

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:

name - the system-dependent filename

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason

FileOutputStream

public FileOutputStream(String name,
                        boolean append)
                 throws FileNotFoundException

Creates an output file stream to write to the file with the specified name. If the second argument is true, then bytes will be written to the end of the file rather than the beginning. A new FileDescriptor object is created to represent this file connection.

First, if there is a security manager, its checkWrite method is called with name as its argument.

If the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason then a FileNotFoundException is thrown.

Parameters:

name - the system-dependent file name

append - if true, then bytes will be written to the end of the file rather than the beginning

Throws:

FileNotFoundException - if the file exists but is a directory rather than a regular file, does not exist but cannot be created, or cannot be opened for any other reason.

close

public void close()
           throws IOException

Closes this file output stream and releases any system resources associated with this stream. This file output stream may no longer be used for writing bytes.

If this stream has an associated channel then the channel is closed as well.

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.

finalize

protected void finalize()
                 throws IOException

Cleans up the connection to the file, and ensures that the close method of this file output stream is called when there are no more references to this stream.

Overrides:

finalize in class Object

Throws:

IOException - if an I/O error occurs.

getChannel

public FileChannel getChannel()

Returns the unique {@link java.nio.channels.FileChannel FileChannel} object associated with this file output stream.

The initial {@link java.nio.channels.FileChannel#position() position} of the returned channel will be equal to the number of bytes written to the file so far unless this stream is in append mode, in which case it will be equal to the size of the file. Writing bytes to this stream will increment the channel's position accordingly. Changing the channel's position, either explicitly or by writing, will change this stream's file position.

Returns:

the file channel associated with this file output stream

public final FileDescriptor getFD()
                           throws IOException

public void write(byte[] b)
           throws IOException

public void write(byte[] b,
                  int off,
                  int len)
           throws IOException

public native void write(int b)
                  throws IOException